problem with colorbar LaTeX title rendering

I am trying to implement a LaTeX math title for my colorbar and plotly is having some trouble rendering it. I am using Python 2.7, Plotly 4.5.2. My code:

fig = go.Figure()
fig.add_trace(go.Scatter(x=x_data, 
                         y=y_data,
                         mode='markers',text=obj_name,name='',
                         marker=dict(symbol='circle',size=12,line=dict(width=1,color='SlateGray'),
                                     opacity=0.75,color=log_mbh,colorscale='Rainbow',showscale=True,
                                     cmin=6.0,cmax=8.0,
                                     colorbar=dict(title=dict(text=r'$\Large\alpha\beta\gamma\delta$',side='top'),
                                                   thickness=50,tickmode='array',tickvals=[6.0,6.5,7.0,7.5,8.0]), 
                                    ),
                         )
             )
fig.add_trace(go.Scatter(x=np.arange(0,300,10), y=np.arange(0,300,10),
                         line = dict(color='LightSlateGray', width=2, dash='dash')))

fig.update_layout(
    template='plotly_white',
    xaxis = dict(showgrid=False,ticks='inside',zeroline=True,zerolinecolor='black',rangemode='tozero'),
    yaxis = dict(showgrid=False,ticks='inside',zeroline=True,zerolinecolor='black',rangemode='tozero'),
    xaxis_title=dict(text=r'$x$'),
    yaxis_title=dict(text=r'$y$'),
    font=dict(size=16),
    showlegend = False,
    autosize   = False,
    width      = 750,
    height     = 750,
    margin     = dict(l=50,r=50,b=50,t=50,pad=10),
)

fig.show()

Which produces the output:

As you can see, the LaTeX title seems to be rotated 90 deg, and ignoring side='top'. I have tried to increase the width of the colorbar and increase the plot's margins to no avail. Is there a workaround or solution for this problem?

首先运行提供的 Python 2.7 和 Plotly 4.5.2 复现代码，然后跟踪 colorbar 标题如何处理 LaTeX 文本和 side='top'。完成的标准是：标题使用所请求的 LaTeX 和顶部方向进行渲染，同时不破坏其他 colorbar 标题。